Electric cables for conveying high current at low voltage, in particular welding cables, are generally constituted by one or more conductors each of which comprises a multitude of elementary strands covered by an outer sheath. So-called cooling channels exist between the conductor(s) and the sheath and provide for the circulation of water required to cool the cables.
However, as the cables are used, the elementary strands are abraded because of electrodynamic vibrations and because of mechanical forces applied thereto, thus causing the cooling channels to become obstructed. Some cables included polyester or polypropylene braids between the conductor(s) and the outer sheath, thereby increasing the risks of obstructing the cooling channels.
Preferred embodiments of the present invention considerably increase the lifetime of the cables by reducing breakages in the elementary strands by means of improved protection of the conductor(s) using a perforated envelope.